CSS can be used in various ways in HTML. One of them is by using Internal CSS i.e. using a <style> tag. The <style> tag is used in the <head>…</head> tag. It defines CSS style for a single page.
Example
You can try to run the following code to use internal CSS in HTML −
<!DOCTYPE html>
<html>
<head>
<style>
h1 {color: red;}
p {font-size: 12px;}
</style>
</head>
<body>
<h1>Tutorials</h1>
<p>We provide free tutorials for engineers and professional.</p>
</body>
</html>